The U.S. Supreme Court on Monday upheld a lower-court decision that ordered California to release as many as 46,000 prison inmates over the next two years. Depending on how the state decides to meet the mandate — by releasing inmates outright, sending them to county jails or some other arrangement — it could have a large impact in Santa Barbara County.

The 5-4 ruling in Brown v. Plata, which was originally filed in 2001, found that inmates in California’s prison system do not receive minimal mental health or medical care, mostly because of overcrowding. The prison system is designed for about 80,000 inmates but currently holds more than 143,000, according to court documents.

Under the order, the state has two years to reduce the total inmate population to about 110,000, a capacity of 137.5 percent. With Monday’s ruling, state officials have two weeks to come up with a plan to meet the requirement.

Experts testified that crowding is the primary cause of the violations. California hasn’t budgeted for enough staff to meet demand — there are high vacancy rates for surgeons and psychiatrists — and even if the positions were filled, there isn’t enough space for more staff, documents state.

“(Crowding) promotes unrest and violence and can cause prisoners with latent mental illnesses to worsen and develop overt symptoms,” the documents say. “Increased violence requires increased reliance on lockdowns to keep order and lockdowns further impede the effective delivery of care.”

The closest state prison is California Men’s Colony, a minimum- and medium-security facility in San Luis Obispo.

The state’s next steps could be felt locally.

“If we have people who should be in prison out on our streets when we’re trying to maintain our resources, which are dwindling, it’s a cause for concern,” Sheriff’s Department spokesman Drew Sugars said.

The county doesn’t have the capacity to house more inmates, and Sheriff Bill Brown’s attempt at funding a new jail through a sales-tax initiative was shot down by voters in November.

Between the Main Jail and Medium Security Facility off of Calle Real, there are typically 900 to 1,000 inmates incarcerated each day, well above the maximum. For the 2011-2012 budget year, the Sheriff’s Department proposes closing the Santa Maria facility and is converting a meeting room in the Main Jail into a 50-bed housing complex for a net gain of 10 beds, Sugars said. The Sheriff’s Department is responsible for the jails.

The extra staff from the North County facility are needed to cover the increased capacity, but the change is estimated to save $1.2 million in personnel costs.

Law-enforcement agencies in the Santa Maria Valley and the California Highway Patrol will then have to transport inmates either to Santa Barbara or Lompoc, however, which could add up to two hours to the trips.

Another attempt to relieve state prison overcrowding is AB 109, which shifts the responsibility of housing lower-level, nonviolent offenders to county jails. Although signed by Gov. Jerry Brown in April, it will only be implemented once the mandate is funded, and as Sugars said, “it’s a pretty big check someone would have to write to make that happen.”

The pressure on local agencies comes at a time when they’re losing positions by the dozens. According to the Sheriff’s Department proposed 2011-2012 budget, 104 full-time positions — or 15 percent — were lost through the last four years of budget cuts.

— Noozhawk staff writer Giana Magnoli can be reached at gmagnoli@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk or @NoozhawkNews. Become a fan of Noozhawk on Facebook.